Roy,
looking through previous discussion of dynamic DNT response headers and "Vary: DNT", about the most extensive explanation I see is:
http://lists.w3.org/Archives/Public/public-tracking/2011Oct/0044.html
> Note that this would require all responses from that server
> to disable shared caching ("Vary: DNT"). I think that is a non-starter.
Just from the protocol definition, that conclusion doesn't follow (using the httpbis draft):
http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-17#section-3.5
I vaguely recall that you had the behaviors of particular implementations in mind in previous discussions.
Care to put on the record in a bit more detail what that was all about?
> If any DNT response is given, it should be restricted to responses
> that are already intended to be non-cacheable (e.g., custom content
> and advertising placements).
Thanks,
--
Thomas Roessler, W3C <tlr@w3.org> (@roessler)